Automatic choke actuator



May 31,1927. 1,630,614

E. J. HIFNER AUTOHATIC CHOKE ACTUATOR Filed May 13. 1926 PATENT OFFICE.

ERNEST J. HIFNER, F LEXINGTON, KENTUCKY.

AUTOMATIC CHOKE ACTUATOR.

Application filed May 13, 1926. Serial No. 108,875.

My invention relates to choke valve actuators.

The invention embodies a device for automatically opening and closingthe choke valve of the carburetor in accordance with the requirements ofthe motor. In the ordinary automobile engine, the choke valve of thecarburetor is normally open so that air may freely enter the carburetorand intake manifold. The choke valve is connected to a device, on theinstrument board of the automobile, by the manipulation of which thechoke valve ma be closed, or opened, at will, by the driver. Thedifliculty encountered in connection with this arraugement is that theoperation of the choke valve requires separate attention, while thevehicle is being driven, and further, it is practically impossible toadjust the choke valve manually, to meet the requirements of the motor,in operation.

In the operation of the ordinary internal combustion engine, of anautomobile, upon starting the engine, particularly when it is cold, thechoke valve is manually actuated so that it is closed. When the enginestarts, the choke valve must be released, or the engine will choke. Theoperation is manual and in no sense automatic.

By the use of myinventiointhe objection able features encountered inconnection with the manually operated choke valve are overcome, and thechoke valve is closed when the engine is not running, and willaccordingly properly function to supply a rich mixture to the cylinders,upon starting, and

the choke valve will be automatically opened as soon as the enginebegins its running operation, and will be held permanently opened duringthe entire running operation of the engine.

The invention further provides a device -which is in the nature 'of anattachment, and which may be placed upon the ordinary carburetor,without alteration thereof.

The invention further provides means whereby air leakage into themanifold, above the carburetor throttle valve, is prevented.

.In the accompanying drawings, forming a part of this specification, andin which like numerals are employed to designate like parts throughoutthe same,

Figure 1 is a side elevation of a device embodying my invention, showingthe same applied to a carburetor,

Figure 2 is a central vertical longitudinal section through the device,parts in elevation, and the piston in the lower position,

Figure 3 is a similar view, with the piston raised,

Figure 4 is an enlarged fragmentary central vert1cal section, similar toFigure 2, and, F igure 5 is a transverse section taken on line 55 ofFigure 2.

In the drawingsfiwherein for the purpose of illustration, is shown apreferred embodiment of my invention, the numeral 10 designates thecylinders of an internal combustion engine, and 11 the intake manifold,connected with the outlet end of a carburetor 12, haying an air intake13. The carburetor 1S equipped with the usual throttle valve 14,actuated by a lever 15, which is operated by the gas lever on thesteering wheel, as'is well known. The air intake pipe 13, which may leadto an air heating jacket or the like, surrounding the exhaust manifold,is equipped with a pivoted choke valve 16, swung by a lever 17 connectedtherewith. This lever has connection with a sufficiently rigid rod orwire 18, to move it in opposite directions, for openmg and closing thechoke valve 16.

of a bracket 20 or the like. The upper end of the cylinder 19 ispreferably internally screw-threaded, for receiving an externallyscrew-threaded end of a head 21, provided at its lower end with adepending annular flange 22, provided with a depending annular plungerseat 23. The head 21 is provided centrally thereof with an opening orbore 24, and a depending annular valve seat 25 preferably surrounds thisopening or bore. The numeral 26 designates a valve disc which isslidably mounted within the annular flange 22, and its downward movementis limited by a stop ring 27, removably mounted within an annular groove28, as shown. This disc valve is provided at its center with an opening29, and it is also provided with preferably diametrically op- 'positelyarranged auxiliary openings 30.

These openings 29 and Y30 are preferably of the same diameter and thecombined cross sectional area of the openings 29 and 30 is preferablyequal to the cross sectional area of the opening or bore 24. The valvedisc 26 is-slidably'mounted within the flange 22. WVhen-the valve disc26 is moved upwardly due to the action of suction above the same, theintermediate portion of this valve disc engages the valve seat 25, andhence the outer openings 30 are cut out of communication with theopening or bore 24. When the valve disc 26 drops to the lower position,resting upon the stop ring 28, the three openings 29 and 30 are incommunication with the opening or bore 24, and since the combined crosssectional area of these openings 29 and 30 is equal to the crosssectional area of the opening 24, the suction within the opening or bore24 will be transmitted freely to the cylinder 19, beneath this valvedisc. The provision of this valve disc with the central opening and theouter opening or openings, is a very important feature of the invention,and the function of the same will be explained more fully, later.

The head 21 has connection with a pipe 31, which leads into the upperportion of the intake manifold 11, above the throttle valve 14, asshown. 1

Mounted to reciprocate within the cylinder 19 is a plunger 32,'havi ng asliding lit therein, and this plunger is connected with a plunger rod33. The lower end of the cylinder 19 is preferably externallyscrewthreaded for engagement with a cap 3-1, having breathing ports 35,whereby the plunger 32 ma move freely. Preferably formed integra withthe cap 34 and depending therefrom is a tubular neck 36, and the plungerrod 33 passes centrally through this neck in spaced relation thereto. Atits lower end the neck 36 is provided with an inwardly projecting flange37, slidably receivin the plunger rod 33 and constituting a gui e forthe same. It is thus seen that the flange 37 will produce the minimumfriction with the plunger rods The lower end of the plunger rod 33 isscrew-threaded, for receiving a cylindrical lock nut 38, and a cap nut39 is also screwthreaded upon this lower end, and is engaged by the locknut. The cap nut receives the upper end of the rod or wire 18 and thisupper end is provided with an enlargement 40, thereby attaching the rodor wire to the cap nut.

A compressible coil spring 41 surrounds the outer end of the plunger rod33 and receives in its 0 posite ends the reduced extensions 42 of eepers43, which are slidably mounted upon the rod 33 and within a protectingtube or sleeve 44.. The sleeve 44 is longitudinally 'adjustably mountedupon the neck 36, and has screw-threaded engagement therewith, for thispurpose, and

may be locked in adjustment, upon this neck, The

choke valve 16 may e swung in either direction, by a slight pressure,such as a half ounce pressure. The weight of the plunger.

32 and associated elements, is sufiicient, when the plunger is released,to return the choke valve to the closed position. The spring 41 is aslight spring, and does aid in returning the choke valve to the closedposition, although the device could operate for this purpose,withoutthis spring. The primary purpose of this spring is not to return the chore valve to the closed position, but to provide a yielding cushion forthe action of the plunger 32, when it is drawn upwardly rapidly, due tothe suction. When this plunger 32" is drawn upwardly rapidly, its 11 perface impinges against the lower face 0 the annular seat23, and thisplunger is held firmly on this seat, as long as the engine is operating,due to the combustion of its fuel. The plunger does not move up and downduring the running of the engine. The annular seat 23 is provided, toprevent the possibility of any air leaking about the periphery of theplunger and hence getting into the intake manifold 11 above the throttlevalve, It is a recognized fact that if a minute amount of air is allowedto enter the intake manifold above the throttle valve, such as, thean'iount of air which could pass through an opcning as small as thepoint of a pin, that the adjustment of the carburetor would be impairedand the engine would not operate roperly, particularly, when runningidle. t is, therefore, essential that some means he provided topositively prevent air pass ing the plunger 32 and entering the intakemanifold. I have found that this can be efl'ectively accomplished byproviding the annular seat 23. The suction acting upon the plunger 32serves to throw it upwardly,

and the plunger will impinge on the seat 23 and the even contact facesof these parts would be readily injured or destroyed. To prevent thehammerin action between these parts, I have provided shock absorbingmeans, including the coil spring 41. This coil sprin is preferably ofsuch a construction that it has the same strength, when almostcompletely compressed, as when only slightly compressed. This coilspring is of such a length that it becomes completely compressed, sothat its turns completely close or contact, at about the same time thatthe plunger 32 contactswith' the seat 23. lunger The contact is madebetween the and its seat a littlein advance of tie comlete closing ofthe spring 41, so that a perect seating of these parts is assured, but

at about the instant of'contact, the turns of the coil spring 41 becomecompletely closed. At about the time the coil spring is being completelyclosed, it offers substantial resistance to the movement of the plunger,and, therefore, will absorb the shocks which prevent undue hammering.Further, if there is any tendency for the Ill) contacting parts of theplun er and seat 23 to wear awa it is obvious t at the spring will beclose at the instant of contact, an hence the hammering action isrelieved. In other words, the parts are so adjusted that the spring iscompletely closed at about the same time that the plunger contacts withits seat, but an instant after this contact whereby a perfect seating ofthe plunger is assured, and hammering eliminated.

The operation of the device is as follows:

Itmay be assumed that the engine is at rest and cold and that it isdesired to start the same. The operator adjusts the as lever on thesteering wheel to the starting position. He then steps upon the starter.The starter turns the crank shaft and reciprocates the pistons. l/Vhenthis occurs, in the beginning the choke valve 16 is closed, and hence arich mixture is drawn into the cylinders. When the engine is thus beingcranked, suction is created in the cylinders which is transmitted to theintake manifold Hand hence to the opening or bore 24. This suctionimmediately acts upon the disc valve 26, shifting it upwardly andholding it upon the upper seat 25, thereby cutting openings 30 out ofcommunication with the opening or bore 24. Hence the suction must betransmitted entirely through the single opening 29 in entering the topof the cylinder 19, for acting upon the plunger The opening 30 isconsiderably reduced with respect to the diameter of the opening 24, andhence the movement of the plunger 32 upwardly is retarded. This isimportant, as it permits the choke valvolG to remain wholly or partlyclosed for a sufficient length of time, when cranking the engine, priorto the combustion of the fuel. Now if the retarding of the movement ofthe plunger 32 upwardly, were attempted to be eflected by means of aheavy coil spring, a spring considerably heavier than the spring 41,satisfactory results could not be obtained. A heavy spring could retardthe movement of the plunger sufficiently, but when the suction wasslightly lowered in the intake manifold, as when the engine becomes moreor less overloaded, this heavy coil spring would return the choke valve16 to the closed position, and hence choke the engine. This is obviouslyeliminated by my arrangement, for the disc valve 26 is seated upwardlyinstantly upon a slight suction in the intake manifold, as by crankingthe engine, and remains permanently seated upwardly during the entireoperation of the engine under the combustion of its fuel, regardless ofthe variance in the load on the engine. When the plunger 32 reaches itsuppermost position, it engages the seat 23 and forms therewith anair-tight joint- By this time, the choke valve has been completelyopened. Assuming that the ignition of the fuel has started, the enginewill operate u on such fuel, and the valve disc 26 and p unger 32 willremain in the uppermost position, durlng this entire operation of theengine. Particular attention is called to the fact that the plunger 32does not fluctuate up and down, during the o eration of the en 'ne uponits fuel. Now s ould the engine ack fire, the pressure in the intakemanifold is at once increased to or above atmospheric pressure, and itis desired that the choke valve close immediately. When this occurs, thevalve disc 26 drops upon the stop ring 28, and all of the openings 29and 30 instantly areplaced in communication with the opening or bore 24and opening 24 thereby placed in communication with the cylinder 19,above the plunger 32, and increase of pressure permits the plunger toquickly return to its lowermost position and close the choke valve. Thisalso occurs when the operation of the engine upon its power, is stopped.Should the carburetor flood, the engine may be cranked, with the chokevalveopen. This is accomplished by adjusting the gas lever on thesteering wheel a little below the normal starting position. This willmore or less close the throttle valve 14, whereby the major portion ofthe suction will be deflected into the cylinder 19. Hence, as soon asthe engine is turned over by the starter, the increased suction willimmediately raise the plunger 32 and retain the SEIIIIGOPGI].

It is to be understood that the form of my invention, herewith shown anddescribed, is to be taken as a preferred example of the same, and thatvarious changes in the shape, size'and arrangement of parts may beresorted to without departing from the spirit of my invention, or thescope of the subjoined claims.

Having thus described my invention, I claim 1. Thecombination with theintake manifold of an internal combustion engine and carburetorconnected therewith, said carburetor having a choke valve and throttlevalve, of a cylinder associated with the intake manifold, a head for thecylinder having' an inner bore in communication with the interior of theintake manifold above the throttle valve, a suction operated valve discmounted within the cylinder beneath the head and adapted to be seated"upwardly against the head, said valve disc having an inner opening inpermanent communication with the inner bore and outer openin ior'openings in communication with said ore when the valve disc is unseatedand out of communication with said bore when the valve disc is seated, aplunger 0 crating within the cylinder beneath the valve disc, andconnecting means between the. Plunger and choke valve.

2. The combination with the intake manifold of an internal combustionengine and carburetor connected therewith, said carburetor havin a chokevalve and throttle valve, a cylin or associated w1th the ntake manifold,a conduit leadin into the mtake manifold and into the cylin er, anautomatic suction operated device to control the communication of saidconduit and the interior of said cylinder, said device when shifted inone direction reducing suohcommunication and when shifted in an oppositedirection increasing such communication, a plunger operating within thecylinder, and connecting means between the plunger and the choke valve.

3. The combination with the intake manifold of an internal combustionengine and carburetor connected therewith, said carburetor having achoke valve, a cylinder associated with the intake manifold, a conduitleading into the intake manifold and into the cylinder, an'automaticsuction valve shifted to its seat by suction within the conduit, saidvalve being so constructed that it affords a reduced communicationbetween the conduit and interior of the cylinder when it is seated andincreases this communication when it is unseated, a plunger within thecylinder beneath the valve, and a connection between the plunger andchoke valve.

4. The combination with the intake manifold of an internal combustionengine and carburetor connected therewith, said carburetor having achoke valve, a cylinder associated with the intake manifold, a conduitleading into the intake manifold and into the cylinder, an automaticvalve shifted to its seat by suction within the conduit,

said valve being so constructed that it affords a reduced communicationbetween the conduit and interior of the cylinder when it is seated andincreases this communication when it is unseated, and suction operatedmeans actuated b the suction in the cylinder and connecte with the chokevalve.

5. The combination with the intake manifold of an internal combustionengine and carburetor connected therewith, said carburetor having achoke valve, a suction-com trol device connected with the intakemanifold and embodying a valve seat and an automatic valve shifted tosaid seat by suction within the manifold, said valve being soconstructed that it aflfords a reduced communication with the manifoldwhen it is seated and increases such communication when it is unseated,a suction operated device acted upon by the suction within the manifoldthrough the medium of the control device, and means connecting thesuction operated device with the choke valve.

6. A suction control device having means for communication with theintake manifold of an internal combustion engine to be acted upon by thevarying suction therein produced by the change in load upon the engine,

till

retor having a choke valve and throttle valve,

of a cylinder associated with the intake manifold, a conduit leadinginto the intake manifold and into one end of the cylinder, at plungerseat arranged within the cylinder, a plunger slidable within thecylinder and having its end engaging the seat when it is shifted in onedirection to the end of its stroke by the suction within the conduit, aplunger rod connected with the plunger, a compressible coil springsurrounding the plunger rod and compressed thereby when the plungermoves toward its seat, the spring being of such a construction that itsturns are completely closed and contact when the plunger engages theseat, and a connection between the plunger rod and choke valve.

8. The combination with the intake manifold of an internal combustionengine and carburetor connected therewith, said carburetor having achoke valve and throttle valve, of a cylinder associated with the intakemanifold, a head mounted upon one end of the cylinder and having aninner bore and an annular flange constituting a plunger seat, said headbeing provided at said bore with a valve seat, a disc valve mountedwithin the annular flange and adapted to be automatically seated againstthe valve seat by suction in said bore, said disc valve having an innerreduced opening in permanent communication with said bore and outeropenings disposed outwardly of said bore, a conduit connectin said borewith the interior of the manifold, a plunger within the cylinder adaptedto move into engagement with the plunger seat, a plunger rod connectedwith the plunger, a slight compressible coil spring surrounding theplunger rod and compressed thereby when the plunger moves toward itsseat, and a connection between the plunger rod and choke valve.

9. The combination with a carburetor having a mixture outlet passageway, of a suction actuated control device having communication with saidpassage way, said device embodying a seat and valve ada ted to engageand disengage the seat, sai valve Ill Hit

being so constructed that it affords a permanent reduced communicationwith the passage way when it is seated and increases such communicationwhen it is unseated, a suction operated device placed in communicationwith the passage way through the medium of the suction control device,and means for connecting the suction actuated device with the chokevalve of the carburetor.

10. In a device of the character described, a suction control devicecomprising a member having a passage and a valve seat adjacent to thepassage, and a suction actuated valve arranged to engage and disengagethe valve seat, said valve having an opening which remains permanentlyuncovered when the valve is seated and unseated, and having additionalopening or openings which are in communication with the passage when thevalve is unseated and out of communication therewith when the valve isseated.

11. A device of the character described, a member having a passage, asuction opcrated device connected with the member, and a suctionactuated valve to control the communication between the passage and thesuction actuated device, said valve being so constructed that it afiordsa permanent reduced communication between the passage and said suctionactuated device when it is seated and increases such permanentcommunication when it is unseated.

12. A suction actuated device embodying a member having a passage and avalve seat adjacent to the passage and a suction actuated valve toengage and disengage the valve seat, said valve having an inner openingin permanent communication with the passage when said valve is seatedand unseated, and outer opening or openings in communication with thepassage when the valve is unseated and out of communication therewithwhen the valve is seated.

18. A suction actuated device including a member having a passage and avalve seat surrounding the passage, and a suction actuated disc valve toengage and disengage the valve seat, said disc valve having a centralopening in permanent communication with the passage when it is seatedand unseated and additional outer opening or openings adapted tocommunicate with the passage when the disc valve is unseated.

14. A suction actuated device including a member having a passage and avalve seat surrounding the passage, and a disc valve to engage anddisengage the valve seat, said disc valve having an opening in permanentalinen'ient with said passage and additional opening or openings out ofalinement with said passage.

15. A suction actuated device including a cylinder, a member closing oneend of the cylinder, said member having a passage and a valve seatsurrounding said passage, a plunger seat surrounding the valve seat, adisc valve arranged to engage and disengage said valve seat and havingan opening in alinement with said passage and additional opening oropenings out of alinement with said passage and a plunger to reciprocatewithin the cylinder and adapted to engage the plunger seat.

In testimony whereof I afiix my signature.

ERNEST J. HIFNER.

